CPU: INTELI HOTPLUG, more code style + tune.
userns: Add kprojid_t and associated infrastructure in projid.h

Implement kprojid_t a cousin of the kuid_t and kgid_t.

The per user namespace mapping of project id values can be set with
/proc/<pid>/projid_map.

A full compliment of helpers is provided: make_kprojid, from_kprojid,
from_kprojid_munged, kporjid_has_mapping, projid_valid, projid_eq,
projid_eq, projid_lt.

Project identifiers are part of the generic disk quota interface,
although it appears only xfs implements project identifiers currently.

The xfs code allows anyone who has permission to set the project
identifier on a file to use any project identifier so when
setting up the user namespace project identifier mappings I do
not require a capability.

Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
userns: Store uid and gid values in struct cred with kuid_t and kgid_t types

cred.h and a few trivial users of struct cred are changed.  The rest of the users
of struct cred are left for other patches as there are too many changes to make
in one go and leave the change reviewable.  If the user namespace is disabled and
CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile
and behave correctly.

Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
+ full sync "cpufreq_interactive.c" with Linux 3.4 -> https://github.com/imoseyon/leanKernel-d2vzw/ [need testing]
block: row: Prevent starvation of regular priority by high priority

At the moment all REGULAR and LOW priority requests are starved as long as
there are HIGH priority requests to dispatch.
This patch prevents the above starvation by setting a starvation limit the
REGULAR\LOW priority requests can tolerate.

Change-Id: Ibe24207982c2c55d75c0b0230f67e013d1106017
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
block: urgent request: Update dispatch_urgent in case of requeue/reinsert

The block layer implements a mechanism for verifying that the device
driver won't be notified of an URGENT request if there is already an
URGENT request in flight. This is due to the fact that interrupting an
URGENT request isn't efficient.
This patch fixes the above described mechanism in case the URGENT request
was returned back to the block layer from some reason: by requeue or
reinsert.

CRs-fixed: 473376, 473036, 471736
Change-Id: Ie8b8208230a302d4526068531616984825f1050d
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
block: urgent request: remove unnecessary urgent marking

An urgent request is marked by the scheduler in rq->cmd_flags with the
REQ_URGENT flag. There is no need to add an additional marking by
the block layer.

Change-Id: I05d5e9539d2f6c1bfa80240b0671db197a5d3b3f
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>

Conflicts:
	block/test-iosched.c

Conflicts:

	block/test-iosched.c

+ ...
block: make auto block plug flush threshold per-disk based

We do auto block plug flush to reduce latency, the threshold is 16
requests. This works well if the task is accessing one or two drives.
The problem is if the task is accessing a raid 0 device and the raid
disk number is big, say 8 or 16, 16/8 = 2 or 16/16=1, we will have
heavy lock contention.

This patch makes the threshold per-disk based. The latency should be
still ok accessing one or two drives. The setup with application
accessing a lot of drives in the meantime uaually is big machine,
avoiding lock contention is more important, because any contention
will actually increase latency.

Signed-off-by: Shaohua Li <shli@fusionio.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
+ "cpufreq_interactive.c": only for testing ...